Sheet-material associating – Associating or disassociating – Sheet associating
Reexamination Certificate
2000-01-27
2001-10-16
Skaggs, H. Grant (Department: 3651)
Sheet-material associating
Associating or disassociating
Sheet associating
C270S058280, C271S213000, C271S217000, C271S220000, C399S410000
Reexamination Certificate
active
06302389
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a sheet treating apparatus, and more particularly it relates to a sheet treating apparatus for successively receiving sheets such as copying paper discharged from an image forming apparatus such as a copying machine, a printing device or a laser beam printer after image formations and for effecting treatment such as alignment and stitching of the sheets and for discharging and stacking the treated sheets onto a stacking portion.
2. Related Background Art
In conventional image forming apparatuses such as printing devices, copying machines, printers or the like, sheets on which images are formed in a main body of the image forming apparatus are temporarily stacked on a treating tray (first stacking means) by a pair of discharge rollers (sheet discharging means) within a sheet treating apparatus, where, sheet treatment such as alignment and stitching of a sheet bundle is effected. Thereafter, the treated sheet bundle is bundle-discharged onto a stack tray (second stacking means) outside the main body by bundle discharging means.
A trailing end of the sheet bundle discharged on the stack tray is detected by a sheet surface height detecting sensor, and, on the basis of detection, an uppermost level of the sheets on the second stacking means is maintained to a predetermined level.
However, in such a conventional apparatus, if the sheet bundle discharged on the second stacking means is curled, erroneous detection of the sheet height is effected by the sheet height detecting sensor, so that the proper sheet height cannot be detected.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a sheet treating apparatus capable of properly detecting a height of sheets on stacking means without being influenced by curl in the sheet discharged on the stacking means and capable of moving an upper level of the sheets to a proper position in an up-and-down direction.
A sheet treating apparatus according to the present invention comprises tray means liftable and lowerable while sheets are stacked on the tray means, a sheet pressing member movable between a pressing position in which the sheets on the tray means are pressed and a retracted position, sheet pressing member driving means for retracting the sheet pressing member when the tray means is lowered and for moving the sheet pressing means to the pressing position when the tray means is lifted, and detecting means for detecting a height position of the sheets on the tray means to stop lifting the tray means.
Further, the sheet pressing member may receive the discharged sheet in the pressing position.
Further, the sheets may be discharged in a sheet bundle and the tray means are lowered and lifted whenever the sheet bundle is discharged.
Furthermore, the sheet pressing member may include an engagement portion for holding a trailing end of the discharged sheet bundle, and a length of the engagement portion may be greater than a flying amount of the discharged sheet bundle.
In addition, the sheet surface height detecting means for detecting the trailing end of the sheet on the tray means may be disposed in the vicinity of the sheet pressing member.
According to the present invention, since there is provided the sheet pressing member capable of pressing the trailing end of the sheet discharged on the tray means with a simple construction and capable of being rotated to the sheet pressing position when the sheet is lifted and being retracted to the retracted position when the tray means is lowered, if curled sheets are stacked, proper sheet height can be maintained and can be detected by the sheet surface height detecting means, whereby the tray means can be maintained in a proper height.
Further, when the sheet is discharged on the tray means, since the sheets on the tray means are pressed, the sheet(s) on the tray means are not moved by the sheet being discharged, thereby not disordering the aligned sheets. Further, since the length of the pressing member is greater than the flying amount of the sheet bundle upon the discharge, the trailing end of the sheet bundle is prevented from being caught by the pressing member thereby not affecting a bad influence upon the alignment, thereby improving the stacking ability for stacking the sheets on the tray means.
REFERENCES:
patent: 5026034 (1991-06-01), Russel et al.
patent: 5098074 (1992-03-01), Mandel et al.
patent: 5350169 (1994-09-01), Hiroi et al.
patent: 5462265 (1995-10-01), Mandel et al.
patent: 5657977 (1997-08-01), Kato et al.
patent: 5742890 (1998-04-01), Kato et al.
patent: 5774778 (1998-06-01), Adachi et al.
patent: 5778300 (1998-07-01), Murakami et al.
patent: 5839048 (1998-11-01), Kato
patent: 5938186 (1999-08-01), Sato et al.
patent: 5951000 (1999-09-01), Sato et al.
patent: 5961110 (1999-10-01), Adachi et al.
patent: 6199853 (2001-03-01), Andoh et al.
patent: 0143167 (1988-06-01), None
Isobe Yoshinori
Kato Katsuhito
Canon Kabushiki Kaisha
Fitzpatrick ,Cella, Harper & Scinto
Skaggs H. Grant
LandOfFree
Sheet treating apparatus and image forming apparatus having... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sheet treating apparatus and image forming apparatus having..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sheet treating apparatus and image forming apparatus having... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2615118